The present invention relates to a sleeper pad (or tie pad) for fastening to at least one outer surface of a railway sleeper (or tie) facing a ballast bed, wherein the sleeper pad comprises or consists of at least one damping layer.
Sleeper pads are known per se from the prior art. They serve inter alia for damping vibrations which occur when traveling over the rails which are arranged on the railway sleeper. In order to achieve this, the damping layer should have the best possible elastic properties. DE 202 15 101 U1 discloses for example a sleeper pad having an elastic plastic layer and a geotextile layer which adheres to the concrete of a concrete body of the railway sleeper. From DE 43 15 215 A1 a sleeper pad is known in which the layer of the sleeper pad enclosed by the ballast bed is a fleece material. AT 506 529 A1 discloses a sleeper pad having an elastic damping layer. With this sleeper pad, on the one hand a randomly oriented fiber layer is provided for form-locking connection between the sleeper pad and the concrete railway sleeper and on the other hand a reinforcement layer of fiber material is provided.
One problem with the elastic properties of the damping layer lies in the fact that very elastic damping layers also ensure that the ballast of the ballast layer is worn away from the area underneath the railway sleepers particularly when heavy vehicles roll over the rails and thus over the railway sleepers. As a result of this there is a considerable expense arising in having to regularly top up the ballast again under the railway sleepers.